Distributor



NOV. 27, 1945. E, ERlCKSON 2,389,845

DISTRIBUTOR Filed Feb. 18, 1943 FIG. I

24:25 v/ w W i F I 3 Ewe/a Erickson INVENTOR.

BY W a ATTORNEY Patented Nov. 27, 1945 2,389,845

UNITED STATES PATENT OFFICE DISTRIBUTOR Ewald Erickson, Watertown, Minn,assignor to Hercules'PowderComp-any, Wilmington, DeL, a corporation ofDelaware Application February 18, 1943, Serial No. 476,293

8 Claims. (01. 222'-310) This invention relates to' an improvement indistributing hoppers for driers and more particularly to distributinghoppers used in'conjunction with continuous driers for material of thewherein reference symbols refer to like parts wherever they occur.Figure 1 is a diagrammatical, vertical, sectional view, taken lengthwiseof the run of the conveyor, of one form of appawet-solids type, such as,curd in the manufacture ratus for the embodiment of the invention. ofcasein. Figure 2 is an enlarged transverse sectional view In the dryingof material of the wet-solids of the distributing hopper, and Figure 3is a type, the temperature and time of drying depart-elevational,part-sectional view of the front pend on: The physical condition,moisture conof the hopper shown in'Figures 1 and 2. tent and fineness ofgrinding of the material; the In Figure 1, a drier I of conventionaldesign type of drier; the volume and temperature of the has an endlessconveyor belt 2 of open mesh top air circulated through the drier; andthe uniextending therethrough. The conveyor belt 2 formit and thicknessof the layer of material is preferably of the sectional type withconspread on the conveyor belt of the drier. tinuous side guards'andwith sections of the mesh It is uniformity and thickness of the layer of.15 fastened to and carried by roller chains at the material as spreadon the conveyor beltof the sides. This type conveyor permits but verylittle drier to which the present invention is directed, sag in theindividual sections of the conveyor as it has been found that unlessthese factors belt. A material to be dried is carried by a spout aprecisely controlled an inferior product will 3 and charged'into adistributing hopper 5 which result. This fact is emphasized in themanufacgo is'superposedtransversely to the conveyor belt 2. ture ofcasein, for if the curd is not spread uni- The material represented by 1s discharged from formly the time of drying is increased to that thehopper 5 is distributed in a layer of uniform required by the thickestportions and, furtherdepth'upon the conveyor belt 2. The belt promore,too thick a layer of curd not only retards gresses the material intodrying chamber 9 of drying but also tends to affect color and qualitythe drier i. adversely. Conversely, too thin a layer forms The-dryingchamber 9 is of conventional deblow-holes and cracks and the drierceases to sign having motor driven fans IQ for blowing dryadequatelfunction. ing medium, such as air, at high velocity over T e p m yObject of this invention s '60 steam heaters (not shown) which arelocated provide means whereby material to be dried is directly below theconveyor belt 2. The air is continuously and uniformly Spread inpredeterheated as it passes over the steam heaters and mined thicknesson a moving conveyor belt. then passes through the material I asdisposed Another object of this invention is to provide on the conveyorbelt 2 in a layer Of uniform means fo a ju g t e t es f e a depth. Theplacing of the material 1 in a layer spread on a moving conveyor belt.of uniform depth'on the conveyor belt 2 as per- Other objects of theinvention will appear hereformed by the hopper 5 enables the heated airinafter the novel features and combinations to uniformly pass throughthe material and, ac-- bein set forth in the appended claims. cordingly,insures a uniform drying of the Generally described, the presentinvention material. comprises a hopper, an adjustable screed secured 40From the drying chamber 9, the material I to the trailing side of saidhopper and extending passes into drying chamber II which has motortowardthe leading side thereof to form a botdriven fans Hl'andsteam heaters(not shown) tom for a portion of the hopper, said adjustable disposedbelow and above, respectively, of the screed adapted to maintainmaterial as disconveyor belt 2. Circulation is similar to that chargedfrom the bottom of the hopper in a; unidiscussed above for chamber 9,with the exception form depth on a surface disposed beneath said thatthe direction of flow of the air is opposite, hopper and in movementthereto, means for as indicated bythe arrows, maintaining an equaldistribution of material as Referring now more specifically to Figure 2charged to the hopper, and means for maintainand Figure 3, thedistributing hopper 5 has a ing an equal distribution of material asdistrough I3 rigidly secured to a pair (if-supports charged from thehopper. M which in turn are secured to the drier l or A preferredembodiment of the invention has other suitable supporting means. Thelower edge been chosen for purposes of illustration and deof the leadingside l3a and the ends I31) and I30 scription and is shown in theaccompanying of the trough are in close proximity to the surdrawingforming a part of the specification face of conveyor belt 2 so thatmaterial charged each end by a threaded rod l9. These rods have theirlower ends hingedly secured to the screed l8 and their upper ends inthreaded engagement with hand-wheels 2B which are rotatably secured bybearing members 2| to the'trough l3. A threaded rod 22 is rigidlysecured to each end of the member I 5 and these rods are in threadedengagement with hand-wheels 23 which are rotatably secured by bearing 24to the trough l3.

The hand-wheels and 23 provide delicate adjustment of the screed I8 andin conjunction with the adjustable member [5 provide considerable rangefor obtaining the proper angle between the screed and the material beingdistributed, thereby providing means for obtaining a smooth surfacewhich is essential to maintenance of uniform depth. The leading edge ofthe screed I8 is terminated in a knife-like edge and it has been foundin distributing wet-solids material that this type edge will maintain areasonably smooth surface on the material.

To maintain equal distribution of the material as charged to the troughI3, through the spout 3, a right and left hand out flight screw lconveyor 25 is provided in the upper portion of the trough. The cuts 26in screw conveyor 25 are progressively reduced in area from the positionof the spout 3. The progressively reduced cuts 26 in the flights ofconveyor 25 throttle the flow of material throughout the length of thetrough. It is appreciated that variable pitch screws can be utilized forthe same purpose, however, it has been found that by providing cuts toachieve this purpose, that adjustments can be made more readily byincreasing or decreasing the area of the cuts as the flowcharacteristics of a particular material necessitate. To maintain equaldistribution of the material as conveyed or discharged from the trougha. right hand and left hand screw conveyor 21 is provided in the lowerportion of the trough l3 and in juxtaposition to the screed l8. Thematerial 1 is uniformly distributed by the conveyor 25 in conjunctionwith the conveyor 21 throughout the length of the trough l3, therebymaintaining a supply of material in contact with the leading edge of thescreed H3 at all times. A gear 28 is rigidly secured to the shaft ofscrew conveyor 21 which gear engages a gear 29 rigidly secured to theshaft of screw conveyor 25. These gears are driven in synchronousrelationship to the rate of travel of the conveyor belt and rate ofcharge of material by suitable means (not shown).

An example of the operation of the invention is given for the spreadingof wet casein curd on th conveyor belt of a drier. The casein isdelivered by spout 3 into the hopper 5. The hopper has a 6-inch cutflight horizontal screw conveyor 25 for distribution of the casein fromthe center feed spout 3 to the outside edges of the drying screen of theconveyor which lie beneath the bottom of the hopper. This distributionis accomplished by using both right and left hand flights which meet ata joint starting point on the shaft of the conveyor directly beneath thesupply spout. The cut-out sections 26 of the conveyor flights vary fromlarger openings near the center to smaller openings further out on theshaft toward the edge of the drying screen. These cut-out sections moveonly enough of the curd to the extreme edge of the drying screen tomaintain the proper supply of. material for spreading at that point. Thelarger cut-out sections near the source of supply allow more of the curdto drop out of the screw conveyor and thus the proper distributionacross the drying screen within the hopper is accomplished. Near thebottom of .the feed hopper 5 and in close proximity to the conveyorscreen is a 4-inch, right and left hand standard screw conveyor 21 whichoperates in the same manner as the cut flight screw conveyor 25 referredto above and which assists the cut fl'ght conveyor in obtaining a moreconstant and even distribution of the curd across the entire bottom ofthe supply hopper. These screw conveyors are rotated by gears 28 and 29which are driven by suitable means (not shown). The speeds of thesescrew conveyors usually run from 8 to 12 R. P. M., therefore, a variablespeed arrangement for the driving means to obtain satisfactory resultswith different types of curd is desirable. The overall possible range ofspeed may be extended somewhat beyond the two limits given, but thelimits as given have been found to be preferable for the handling ofcurd. The action of the screw conveyors on the curd charged to thehopper'is shown specifically in Figure 2, wherein la. represents theaverage level of material in the trough and lb represents theapproximate maximum height of material at the carrying side of theflights, when average loading is maintained. The hopper 5 has no bottomexcept for an adjustable shelf or screed 18 covering a portion of thebottom area on the side toward the drier. The hopper edges, therefore,must extend to within about /2-inch or less of the top of the conveyorscreen, and the movement of the conveyor screen under the bottom of thehopper causes the curd to be carried on the screen from the hopper. Withthis arrangement, the conveyor screen is self-loading and the partialbottom or screed of the hopper permits varying the depth of curd theconveyor screen is permitted to carry out from under the hopper. In thismanner, a layer of casein curd of uniform depth is disposed on thesurface of the conveyor screen.

It is evident that there are numerous factors which will influenceconditions for the most satisfactory operation of the invention, theactual limits of which cannot be established except by a detailed studyof the materials to be distributed and the intermediate and finishedproducts involved. In this respect, it will be seen in distributing somematerials, such as surfacing material over a non-traveling surface, thata traveling mo tion impartedto the hopper will achieve the resultscontemplated by the invention.

While the present invention has been drawn primarily to the distributionof wet casein curd. materials of many kinds. such as sulp ur slud e.phosphate fertilizer, calcium carbonate, mafinesium carbonate, limeputty and surfacin materials, are efficiently distributed in accordancewith the invention.

The advantages of the present invention reside in the application of alayer of material of uniform depth throughout, and in conjunction withdrying apparatus, the speed of drying, the uniformity of drying, and theprevention of blows by distribution of the material in absoluteuniformity to achieve a uniform resistance to the drying mediumcirculated therethrough.

What I claim and desire to protect by Letters Patent is:

1. A material distributor comprising a hopper superposed transversely toa continuou foraminous conveyor belt, a supporting member adjustablysecured to the trailing side of said hopp an adjustable screed memberhingedly secured to said supporting member and extending toward theleading side of the hopper to form a bottom for a major portion of thehopper, said adjustable screed member adapted to screed material ascarried by the conveyor belt from the hopper, a rod member having itslower end hingedly secured to the adjustable screed member near theleadmg edge thereof and extending upwardly therefrom,

said rod member adapted to provide support to the leading edge of thescreed member, means for adjustably securing the upper end of the rodmember to adjust the leading edge of the screed member relative to theconveyor belt, separate means for adjusting relative to the conveyorbelt the supporting member and the edge of the screed member which issecured to the supporting member, means for maintaining an equaldistribution of material as charged to the hopper, and means formaintaining an equal distribution of material as discharged from thehopper.

2. A material distributor comprising a hopper superposed transversely toa continuous foraminous conveyor belt, an adjustable member hingedlysecured to the trailing side of said hopper and extending toward theleading side thereof to form a bottom for a major portion of the hopper,said adjustable member adapted to screed material as carried by theconveyor belt from the hopper, a-

right and left hand screw conveyor for maintaining an equal distributionof material as centrally charged to the hopper, and a right hand andleft hand screw conveyor for maintaining an equal distribution ofmaterial as discharged from the hopper.

3. A material distributor comprising a hopper superposed transversely toa continuous foraminous conveyor belt, a supporting member adjustablyaffixed to the trailing side of the hopper, an adjustable memberhingedly secured to said supporting member, said adjustabl memberextending toward the leading side of said hopper to form a bottom for amajor portion of the hopper and adapted to screed material as carried bythe conveyor belt from the hopper, means in association with theadjustable member and the supporting member, respectively, forexternally adjusting the hopper bottom relative to the conveyor belt, aright and left hand screw conveyor for maintaining an equal distributionof material as centrally charged to the hopper, and a right hand andleft hand screw conveyor for maintaining an equal distribution ofmaterial as discharged from the hopper.

4. A material distributor comprising a hopper superposed transversely toa continuous foramiall) nous conveyor belt, a supporting member adjustably afiixed to the trailing side of the hopper, an adjustable memberhingedly secured to said supporting member, said adjustable memberextending toward the leading side of said hopper to form a bottom for amajor portion of the hopper and adapted to screed material as carried bythe conveyor belt from the hopper, means in association with theadjustable member and the supporting member, respectively, forexternally adjusting the hopper bottom relative to the conveyor belt, aright and left hand out flight screw conveyor for maintaining an equaldistribution of material as centrally charged to the hopper, and a righthand and left hand screw conveyor for maintaining an equal distributionof material as discharged from the hopper.

5. The material distributor according to claim 4 wherein said right andleft hand out flight screw conveyor has the cuts in the flights thereofprogressively reduced in area from the point of material charge.

6. The material distributor according to claim 4 wherein said adjustablemember has the leading side thereof terminating in a knife-like edge.

7. A distributor of the class described havin in combination a hopper,an adjustable screed secured to the trailing side of said hopper andextending toward the leading side thereof to form a bottom for a majorportion of the hopper, said adjustable screed adapted to maintainmaterial as discharged from the bottom of the hopper in a uniform depthon a surface disposed beneath said hopper and in movement thereto, a rodmember having its lower end hingedly secured to the adjustable screednear the leading edge thereof and extending upwardly therefrom, said rodmember adapted to provide support to the leading edge of the screed,means for adjustably securing the upper end of the rod member to adjustthe leadin edge of the screed member relative to the said surface,separate means for adjusting relative to the conveyor belt the edge ofthe screed member which is secured to the trailing side of the hopper,means for maintaining an equal distribution of material as charged tothe hopper, and means for maintaining an equal distribution of materialas discharged from the hopper,

8. A distributor of the class described having in combination a hopper,an adjustable screed secured to the trailing side of said hopper andextending toward the leading side thereof to form a bottom for a majorportion of the hopper, said adjustable screed adapted to maintainmaterial as discharged from the bottom of the hopper in a uniform depthon a surface disposed beneath said hopper: and in movement thereto, aright and left hand screw conveyor for maintaining an equal distributionof material as centrally charged to the hopper, said screw conveyorhaving cut flights, the cuts of which are progressively reduced in areafrom the position of material charge, and a.

right hand and left hand screw conveyor for maintaining an equaldistribution of material as discharged from the hopper.

EWALD ERICKSON.

